Comments: Looks good. The cod has lots of extra things that aren't needed.

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The video is a nice touch.

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</pre>

== Overview ==

== Overview ==

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My mini project 2 is using an Adafriut 8*8 red LED matrix to show 2 animations. First animation is to composite a diamond and then fade out. The second animation is to drop down a horizontal bar to the bottom of the LED matrix until all the lines are being filled. When the two animations were done, the LED matrix will flash 5 times and shut down.

My mini project 2 is using an Adafriut 8*8 red LED matrix to show 2 animations. First animation is to composite a diamond and then fade out. The second animation is to drop down a horizontal bar to the bottom of the LED matrix until all the lines are being filled. When the two animations were done, the LED matrix will flash 5 times and shut down.

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The code that being used in this project is modified from the sample code provided by Dr. Mark A. Yoder. The new version of the code that contained my animation has been commited to my github which you can find at here: [https://github.com/1984xiali/lix_beaglebone Mini-project 2 by Xia Li].

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The code that being used in this project is modified from the sample code provided by Dr. Mark A. Yoder. The new version of the code that contained my animation has been commited to my github which you can find at here: [https://github.com/1984xiali/ECE497_mini_project2 Mini-project 2 by Xia Li].

== Wire Connection ==

== Wire Connection ==

The wire connection part is not very complex. As you can see in the picture

The wire connection part is not very complex. As you can see in the picture

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<span style="color:red">Which header are you using? It looks like P9</span>

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pin3 VDD3.3v ----> breadboard's positive(red line)

pin3 VDD3.3v ----> breadboard's positive(red line)

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[[File:Wire connection.jpg|500px]]

[[File:Wire connection.jpg|500px]]

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Here is a hand by hand tutorial about I2C wrote by Dr. Yoder. If you need that [http://www.elinux.org/EBC_Exercise_12_I2C Click here].

Latest revision as of 18:50, 14 November 2012

Contents

Overview

Overview: 2
Wiring: 1, Include the header number
Code: 1, Clean it up some more.
git/Compiles with make: 2 make works
Demo: 2
Total: 8
Comments: Looks good. The cod has lots of extra things that aren't needed.
The video is a nice touch.

Overview

My mini project 2 is using an Adafriut 8*8 red LED matrix to show 2 animations. First animation is to composite a diamond and then fade out. The second animation is to drop down a horizontal bar to the bottom of the LED matrix until all the lines are being filled. When the two animations were done, the LED matrix will flash 5 times and shut down.

The code that being used in this project is modified from the sample code provided by Dr. Mark A. Yoder. The new version of the code that contained my animation has been commited to my github which you can find at here: Mini-project 2 by Xia Li.

Wire Connection

The wire connection part is not very complex. As you can see in the picture
Which header are you using? It looks like P9

pin3 VDD3.3v ----> breadboard's positive(red line)

pin45 GND ----> breadboard's negative(blue line)

pin19 i2c2_SCL ----> LED matrix's c pin

pin20 i2c2_SDA ----> LED matrix's d pin.

Don't forget the two 4.3KΩ pull-up resistors.

LED matrix's + - pin ----> breadboard's positive and negative

The wire connection picture:

Here is a hand by hand tutorial about I2C wrote by Dr. Yoder. If you need that Click here.

Software Design

Important facts

After I went through the sample code. I found several points which are very important. You may need to understand before you move on:

1. i2cbus is 3

2. i2c address is 0x70

3. oscillator daddress is 0x21

4. display on daddress is 0x81

5. Full brightness is 0xE7

6. array smile_bmp[], frown_bmp[], and neutral_bmp[] are save the hex-decimal value for each line on LED matrix

Theory

The theory is when you convert the hex-decimal value of each line to binary value, you will get a 8 bit binary number for each line. Each bit will stand for each led point on the corresponding line. 0 for off, 1 for on.